#include<iostream>
#include<iomanip>
using namespace std;

int main()               //求样本空间里样本数据的均值
{
    int n;
    cin >> n;
    double sum = 0;
    double average = 0;
    double a;
    for(int i = 0;i<n;i++)
    {
        cin >> a;
        sum = sum + a;
    }
    average = sum / n ;
    cout << average << endl;
    return 0;
}